West Africa's oldest city, Kano dates back at least 1,000 years. In the 1800's, mud-walled Kano was home to a very important marketplace. Today, it remains a vital commercial and industrial city. Twice a year, riders on horseback charge through the city to honor a local leader as part of a 200-year-old tradition known as the Durbar Festival. (SAURABH DAS—AP)